1. Field of the Invention
The present invention relates to a gear support for mounting a gear on a motor vehicle, in particular for axle gears, with an elongate carrier portion which is oriented along the longitudinal axis, with a flange portion at one end of the carrier portion, the flange portion serving for fastening the gear support to a case of the gear, and with a bearing portion in the region of an opposite end of the carrier portion, the bearing portion serving for mounting the gear support on the motor vehicle.
The present invention relates, furthermore, to a gear having such a flanged-on gear support.
2. Description of the Related Art
Gears (transmissions) are mounted on a motor vehicle, as a rule, at a plurality of suspension points. The bearing points must be suitable for supporting reaction moments which result from the fact that torques are transmitted via the gear.
In this respect, it is known to provide projecting gear supports on the gear case, in order to provide bearing points spaced apart from the case of the gear. This can serve, on the one hand, to “achieve” favorable bearing points on the motor vehicle. Also, the use of such gear supports can serve to increase the lever arm for absorbing the reaction moments. As a result, the reaction forces are reduced and it becomes possible to use softer rubber bearings. This leads, as a rule, to a better acoustic behavior of the drive train.
Examples of such gear supports are disclosed in the publications DE 196 24 002, DE 34 42 584, DE 196 23 936 C1 and DE 100 20 079 C1.
The gear supports are integrated partially into the case of the gear (for example, 100 20 079 C1) or are designed as separate elements (for example, DE 85 21 933 U1).
Furthermore, it is known from the drive train of the Porsche 996 with four-wheel drive to flange on the front-axle differential a gear support which, starting from the case of the front-axle differential, surrounds the cardan shaft. This gear support forms the closest prior art and has an elongate carrier portion in the form of a tube of approximately rectangular cross section. At one end of the carrier portion, a flange portion is provided, which serves for fastening to the case of the gear. In this instance, the flange portion may form part of the case, a shaft seal then, as a rule, being integrated into the flange portion in order to seal off the cardan shaft. At the other end of the carrier portion, a bearing portion in the form of an approximately circular lug integrally formed so as to be offset laterally with respect to the carrier portion is provided. A rubber bearing can be inserted into the lug. The gear support is produced by sand casting as a profile cast in one part.
Furthermore, it is known to design such gear supports as a drawn tube with pressed-in or welded-on end pieces which are produced as castings or forgings.
This type of design is comparatively costly in terms of production, since the gear support is produced from three individual parts which have to be joined together.
The gear support at the front-axle differential of the Porsche 996 is likewise comparatively uneconomical in terms of production.
In general, the acoustic behavior of such gear supports is also a problem. When a toothing of the drive train causes excitation, large closed radiation surfaces radiate airborne sound in the resonant range.